Bats, man!

I've had several friends ask recently for my opinion on the new report soon be released by the International Programme for the State of the Ocean on the magnitude and prospective impacts of major threats facing the marine environment. The article has been covered by multiple media outlets already, including Yahoo and Time, among others, but the full report has not yet been released. So, I shall withhold my review until I can see the full doc...

In the meantime, I have to share my recent experience viewing the nightly emergence of Mexican free-tail bats from their haunts underneath the Congress Street Bridge in Austin, Texas. The name of these airborne mammals comes from their abnormally long (for bats, anyway) tails that extend beyond the terminal membrane. The Austin colony numbers somewhere between 750,000 and 1.5 million bats, and is reputed to be the largest urban bat colony in the world. As impressive as those numbers sound, the largest colonies in natural caves outside of urban areas can number in the tens of millions.

Still, the nightly fly-out by the bats in the Austin colony is an impressive phenomenon. Unlike the colonies in more remote locales, the more modest Austin colony provides some very unique benefits. Firstly, the bats collectively consume somewhere in the neighborhood of 30,000 pounds of insects every night. As I ran and paddled along the Colorado River/Lady Bird Lake, I was bugged (pun fully intended) by surprisingly few mosquitoes, gnats, etc., and I thank the little bats for that.

Secondly, the colony provides a very unique and accessible wildlife viewing opportunity. Like the famous sea lions residing at San Francisco's Pier 39, not to mention the many river herring runs along the Atlantic coast that inspired the name of this blog (perhaps best watched at Maine's Damariscotta Mills fish ladder), the bats offer a chance to see abundant, active wildlife without journeying to remote parts of Africa, or the Amazon, or the high Rockies. And, believe me, it's well worthwhile!

Although there are several bridges cross the river/lake, only the Congress Street Bridge houses bats. That is due to the unique structure of the bridge, with a series of narrow open seams underneath that provide a perfect place for bats to shelter:

At first, a few bats begin to appear just past 8PM, and flit about underneath the bridge or above the adjacent parkland where some of the visitors assemble to watch. The earliest bats to emerge seem hesitant to roam too far. Or, perhaps there are ample insects nearby on which to feed, which soon scatter or are all consumed, causing the bats to head further afield. They might also still be a little sleepy and therefore not quite ready for a longer foray, as perhaps evidenced by this little guy that landed on the bag of the lady seated next to me on the lawn (and note the long "free" tail):

The small numbers of bats that emerged early and stayed pretty close to home soon disappeared back into their crevices by 8:20PM or so. Things were quiet for a spell, and then rather suddenly right around 8:30PM, they started emerging in droves. A veritable river of bats took shape and headed out along the actual river and over the top of the bankside trees. I watched this mass exodus from below for a few minutes, before heading up onto the bridge to take in the broader landscape view. And it was quite the sight! This photo does not do justice the spectacle, but you get the idea:

I had been to Austin several times before this trip, but always at the wrong time of the year to watch the bats (although at much better times of year temperature-wise: 106 - ouch!). I'm glad I finally got to see them, for it was one of the the coolest things I've seen. I highly recommend checking out the nightly flight of these Mexican free-tails, as I will certainly do whenever my travels take me to Austin in the summer from now on!

The force of nature

Although I'm still reveling in the natural wonders encountered during my time in Oregon, it's important to remember that while I was having fun, others have been experiencing the power of nature in a very different way. The catastrophic effects of some severe climactic and geological events recently have left many suffering. The tsunami in Japan, the flooding along the Mississippi, and a rash of tornadoes across the southeastern U.S. present sobering reminders that nature can be as destructive as she is beautiful.

Images of devastation and suffering have not been lacking. We have seen houses flattened and submerged, cars and trucks carried along in floodwaters like toys, and people young and old surveying their losses with looks of forlorn desperation.

This link provides a very different perspective on the devastation. It shows the path of the April 27 tornado that tore across Tuscaloosa, Alabama from space. It left a path wider than nearby rivers and freeways, and gives a whole new perspective on the force nature can exert upon the landscape and its inhabitants.

Mmmm, beer.

I just returned from a fantastic vacation to Oregon, one that should provide fodder for a few posts following this one. Not only did the Beaver State present all sorts of natural wonders to write about, but I also spent a few days with a friend who is a very successful writer. Just being around him tends to inspire me to put pen to paper (or finger to keyboard, at least). That combination caused me to shake Running On awake from its most recent slumber...

Of course, in addition to letting me spend time with friends and letting me experience some spectacular places, Oregon also introduced me to some outstanding craft beers. I have to admit, the state's self-proclaimed status as micro-brew capital of the U.S. seems to be warranted. A particular favorite, due in part to their beer and in part to a fun bartender and tasty ribeye, was Golden Valley Brewery in McMinnville. Also, its waterfront location in Newport, overwhelming diversity of brews, and the rich smell of yeast permeating the air made the Rogue Brewery a memorable spot as well.

Quite serendipitously, upon returning to the Bay State, I came across an interesting article on the state of craft brews generally and organic brews specifically in the U.S. And it seems that things look good! Craft brews account for around 5% of U.S. beer sales by volume and 7.6% by value (given the higher price point). Both figures represent continued growth, with analysts predicting that sales could reach 20% over the next decade.

Within that market, organic brews still represent a small fraction of the 1,716 craft brews in the country. However, sales of organic brews increased nearly fivefold from 2003 to 2009, from $9 million to $41 million. That is the fastest growth of any sector of the U.S. beer market.

And, fittingly, to close our time in Oregon (for now) we had our last beer at the PDX location of the organic Laurelwood Brewery!

New discoveries!

I signed off in 2010 by sharing the very welcome discovery of a nesting pair of Harpy eagles in the mountains of believe. Not to be outdone, 2011 has kicked off with reports of some exciting discoveries of its own:

Firstly, a previously unknown area of healthy, pristine coral reef has been discovered in deep waters (at least as far as reefs are concerned, i.e., 100-500 feet) off the southwest corner of Puerto Rico. Often, reefs in deeper waters are more low-relief and generally less topographically complex than those in shallow waters. That means they often support lower diversity and abundance than shallow reefs.

But it does not mean they are less ecologically important. Deepwater reefs can be home to very different species than shallow reefs, so they harbor unique biodiversity. For those species held in common between deep and shallow reefs, the deeper habitat can serve as a refuge to buffer the population against natural or anthropogenic impacts, such as storms and fishing, which typically have more severe impacts in shallower water. Also, low-relief deepwater reef habitat can serve to link larger and more complex shallow habitat areas as a sort of underwater highway, or at least as a series of stepping stones across open and unsheltered bottom (for a stimulating discussion of this function, see this fine volume).

Of course, the couple of photos provided in the article on the discovery of these reefs linked above suggest that these might be more complex and higher relief reefs than one might expect in deep water. Sure, 100-500 feet is really not that deep in comparison with some truly deepwater corals (i.e., 400-2000 meters, not feet!), so we might be looking at something more akin to shallow reefs than deep.

In any case, there are many exciting scientific questions waiting to be addressed concerning the species composition and ecological function of these reefs, both in their own right and in relation to other nearby shallower reefs. Perhaps more importantly, hopefully we will implement quick and aggressive conservation measures for these reefs to get ahead of the curve and ensure that we do not lose their lessons and value before they can be understood…

A second discovery is that of a new and very unique species of freshwater crayfish in the streams of Tennessee. It’s also a very large crayfish, and interestingly has oddly “bearded” antennae. Reports of this discovery note that, while finding new species in remote jungles of Borneo or in the depths of the ocean is neither uncommon nor entirely unexpected, finding new species in very accessible streams of a highly populated and developed nation like the U.S. is unusual. I agree – that’s pretty cool. Like the newly discovered Puerto Rican reefs, this species lives in deeper parts of streams, and also seems to be in fairly low abundance, which together perhaps explain why it has escaped out attention. And, like those new reefs, hopefully we will act quickly to understand and protect this newly discovered beast…

Finally, a personal new discovery, albeit one long known to science: I’ve been working my way through the BBC’s excellent “Life” series (the follow-up to its celebrated “Planet Earth”). In the “Fish” episode, I was introduced to the – and I still cannot believe this name – Sarcastic Fringehead, which lives in water off the U.S. Pacific coast. In many ways, this fish seems to be a Pacific version of one of my favorite Atlantic species, the oyster toadfish. Both live in patches of structured habitat amidst areas of open sand, and both are ambush predators and aggressively territorial.

But where the fringehead – and it pains me to say this – perhaps proves the superior species is its amazing territorial contests, which cannot be adequately described and really need to be seen. Of course, toadfish exhibit some impressive vocalizations, and I’m not sure whether fringeheads do or not, so maybe the determining factor is whether one has more of an audio or visual inclination? Or, maybe both species should just be appreciated for their undeniable coolness and not ranked?

In any case, 2011 has presented some fascinating discoveries so far, and hopefully will continue to provide many more!